We propose a novel strategy to measure low levels of growth hormone in small children and adolescents. This employs the immuno-polymerase chain reaction (PCR) to amplify DNA tagged to antibody-antigen complexes. Unlike conventional PCR, this allows measurement not of DNA sequence but of antigenic determinants, and dramatically increases the sensitivity of conventional ELISA or RIA protocols. This protocol should allow measurement of human growth hormone (hGH) in samples of urine or saliva, as opposed to the standard serum assay. Thus, this will provide a noninvasive test to allow multiple hGH measurements, without the associated visits to a practitioner for blood sampling. Because hGH measurement and supplementation affects at least 3% of the youth population, this should provide a standardized, reproducible, and non- invasive clinical test to monitor deficiencies in this key hormone, as well as to provide a means to monitor progress after hGH supplementation regimens.